India’s first cable-stayed bridge: Vidyasagar Setu and other

Huge bridges over big rivers and sea creeks are marvels of engineering. One special kind is the cable-stayed bridge, whose taut cables running from tall towers catch the eye from far away. India's first cable-stayed bridge is Kolkata's Vidyasagar Setu.

What is a cable-stayed bridge?

A cable-stayed bridge has one or more tall towers (pylons). Straight, slanting steel cables run from these towers and hold up the deck of the bridge (the part with the road). Seen from above, the cables look like a fan or the strings of a veena.

How it differs from a suspension bridge

Suspension bridge: one thick main cable hangs like a swing between two towers, and smaller cables hanging from it hold up the deck. Lakshman Jhula and Ram Jhula in Rishikesh are well-known examples.
Cable-stayed bridge: the cables run straight from the tower to the deck, with no main hanging cable in between. These are economical and strong for large bridges of medium span.

Vidyasagar Setu (the Second Hooghly Bridge)

Vidyasagar Setu, which links Kolkata and Howrah, crosses the Hooghly river and was opened to traffic on 10 October 1992. It is named after the great social reformer Ishwar Chandra Vidyasagar. It is India's first cable-stayed bridge, and when it opened it was counted among the longest cable-stayed bridges in Asia. Its main span (the middle stretch) is about 457 metres long.

Did you know? The first bridge over the Hooghly is the Howrah Bridge (Rabindra Setu, 1943), a "cantilever" bridge — it has no cables but huge steel frames, and it was built with rivets instead of nuts and bolts.

Some other famous cable-stayed bridges in India

Bandra-Worli Sea Link (2009), Mumbai: built over the sea, this bridge links Bandra and Worli in Mumbai and has become a symbol of the city.
Signature Bridge (2018), Delhi: the tall, leaning tower of this bridge over the Yamuna can be seen from afar, and a viewing gallery has been built at the top.
Anji Khad Bridge, Jammu and Kashmir: built on the Udhampur–Srinagar–Baramulla rail project over a deep gorge, it is India's first cable-stayed railway bridge.

Why is building a bridge so hard?

Big bridges must carry not only their own heavy weight and that of the vehicles, but also stand up to strong winds, earthquakes, changes in temperature and the flow of the river. That is why their design pays special attention to wind-tunnel tests, computer models and strong foundations. The cables also need regular checks and maintenance.

The advantages of cable-stayed bridges

Cable-stayed bridges need fewer piers in the middle of the river, so they get less in the way of ships and the river's flow. They can be built fairly quickly and are economical for spans from 200 metres up to about a kilometre.

For the exam, in one line

India's first cable-stayed bridge: Vidyasagar Setu (Kolkata, 1992) · First cable-stayed railway bridge: Anji Khad (Jammu and Kashmir).

India’s first cable-stayed bridge: Vidyasagar Setu and other famous bridges